Rome, March 16 : Italian Prime Minister Giuseppe Conte on Friday deplored the "cowardly" gun attacks by suspected white supremacists at two mosques in Christchurch, New Zealand, which left at least 49 people dead and wounded over 20.

"Dismayed over the events in New Zealand. My condolences for the victims and my heartfelt thoughts to those injured in the cowardly gun attacks," Conte tweeted.

"Defenceless people were targeted while they were in a place of worship. Any of intolerance, hatred and violence is unacceptable," the tweet added.

Friday's mosque attacks, the worst mass shootings in New Zealand's history, have drawn international condemnation.

Four people - three men and a woman - were held over the attacks. One was charged with murder and one was released, according to police.

Police discovered explosive devices attached to cars and commissioner Mike Bush was the situation was still "evolving". He urged all mosques in New Zealand to close for the time being.

Muslims make up 1 percent of New Zealand's population and three-quarters were born overseas, according to a 2013 survey.